The Complete Power Conversion Chart
Reference tables converting kW to amps, horsepower, BTU per hour, kVA, and refrigeration tons at multiple voltages and power factors, plus a live calculator.
Common conversions
| Input | Result |
|---|---|
| 5 A @ 240 V | 1.20 kW |
| 10 A @ 240 V | 2.40 kW |
| 15 A @ 240 V | 3.60 kW |
| 20 A @ 240 V | 4.80 kW |
| 30 A @ 240 V | 7.20 kW |
| 40 A @ 240 V | 9.60 kW |
| 50 A @ 240 V | 12.00 kW |
| 100 A @ 240 V | 24.00 kW |
The math behind it
- kW = (A × V) / 1000 = (50 × 240) / 1000
- kW = 12 kW
- HP = 12 / 0.7457 ≈ 16.09 HP
- BTU/hr = 12 × 3412.14 ≈ 40,946 BTU/hr
- Tons = 12 / 3.5169 ≈ 3.41 tons
Everything you need to know
This page collects the full reference charts behind the calculator above: amps to kW at three common voltages, kW to horsepower, kW to thermal output, kW to apparent power at several power factors, and a three-phase amperage chart. Every table below assumes the stated voltage and power factor; for anything outside these exact values, use the live calculator instead of interpolating by eye.
Amps to kW at 120V, 240V, and 480V (single-phase reference, PF 1.0)
These figures assume a purely resistive load. Real 480V circuits are almost always three-phase in practice, so the 480V column here is a single-phase reference point only, useful for spot-checking a three-phase result divided across phases, not a substitute for the three-phase table further down.
| Amps | kW @ 120V | kW @ 240V | kW @ 480V |
|---|---|---|---|
| 5 A | 0.60 kW | 1.20 kW | 2.40 kW |
| 10 A | 1.20 kW | 2.40 kW | 4.80 kW |
| 15 A | 1.80 kW | 3.60 kW | 7.20 kW |
| 20 A | 2.40 kW | 4.80 kW | 9.60 kW |
| 25 A | 3.00 kW | 6.00 kW | 12.00 kW |
| 30 A | 3.60 kW | 7.20 kW | 14.40 kW |
| 40 A | 4.80 kW | 9.60 kW | 19.20 kW |
| 50 A | 6.00 kW | 12.00 kW | 24.00 kW |
| 60 A | 7.20 kW | 14.40 kW | 28.80 kW |
| 80 A | 9.60 kW | 19.20 kW | 38.40 kW |
| 100 A | 12.00 kW | 24.00 kW | 48.00 kW |
| 125 A | 15.00 kW | 30.00 kW | 60.00 kW |
| 150 A | 18.00 kW | 36.00 kW | 72.00 kW |
| 200 A | 24.00 kW | 48.00 kW | 96.00 kW |
Amps to kW, three-phase (line-to-line, PF 0.9)
Commercial and industrial services are usually three-phase. This chart applies kW = (√3 × V × A × PF) / 1000 at a typical mixed-load power factor of 0.9. A resistive three-phase load would sit higher, at PF 1.0, use the calculator above to check that case exactly.
| Amps | kW @ 208V | kW @ 400V | kW @ 480V |
|---|---|---|---|
| 10 A | 3.24 kW | 6.24 kW | 7.48 kW |
| 20 A | 6.48 kW | 12.47 kW | 14.96 kW |
| 30 A | 9.73 kW | 18.71 kW | 22.45 kW |
| 50 A | 16.21 kW | 31.18 kW | 37.41 kW |
| 75 A | 24.32 kW | 46.77 kW | 56.12 kW |
| 100 A | 32.42 kW | 62.35 kW | 74.82 kW |
| 150 A | 48.64 kW | 93.53 kW | 112.24 kW |
| 200 A | 64.85 kW | 124.71 kW | 149.65 kW |
kW to horsepower
Mechanical (imperial) horsepower and electrical horsepower use slightly different constants, 0.7457 kW and 0.746 kW respectively. The gap is small, about 0.05%, but it compounds across a facility with many motors specified to different standards.
| kW | HP (mechanical) | HP (electrical) |
|---|---|---|
| 0.5 kW | 0.67 HP | 0.67 HP |
| 1 kW | 1.34 HP | 1.34 HP |
| 2 kW | 2.68 HP | 2.68 HP |
| 3 kW | 4.02 HP | 4.02 HP |
| 5 kW | 6.71 HP | 6.70 HP |
| 7.5 kW | 10.06 HP | 10.05 HP |
| 10 kW | 13.41 HP | 13.40 HP |
| 15 kW | 20.12 HP | 20.11 HP |
| 20 kW | 26.82 HP | 26.81 HP |
| 30 kW | 40.23 HP | 40.21 HP |
| 40 kW | 53.64 HP | 53.62 HP |
| 50 kW | 67.05 HP | 67.02 HP |
| 75 kW | 100.58 HP | 100.54 HP |
| 100 kW | 134.10 HP | 134.05 HP |
kW to BTU/hr and refrigeration tons
HVAC equipment is rated in BTU/hr or tons rather than kW. One ton of refrigeration equals 12,000 BTU/hr, the rate needed to melt one short ton of ice in 24 hours, or 3.5169 kW.
| kW | BTU/hr | Tons |
|---|---|---|
| 1 kW | 3,412 BTU/hr | 0.28 tons |
| 2 kW | 6,824 BTU/hr | 0.57 tons |
| 3 kW | 10,236 BTU/hr | 0.85 tons |
| 5 kW | 17,061 BTU/hr | 1.42 tons |
| 7 kW | 23,885 BTU/hr | 1.99 tons |
| 10 kW | 34,121 BTU/hr | 2.84 tons |
| 15 kW | 51,182 BTU/hr | 4.27 tons |
| 20 kW | 68,243 BTU/hr | 5.69 tons |
| 30 kW | 102,364 BTU/hr | 8.53 tons |
| 50 kW | 170,607 BTU/hr | 14.22 tons |
| 75 kW | 255,911 BTU/hr | 21.33 tons |
| 100 kW | 341,214 BTU/hr | 28.43 tons |
kW to kVA at various power factors
Apparent power (kVA) rises as power factor falls, since kVA = kW / PF. Generators, UPS units, and transformers are rated in kVA, so this table shows how much apparent-power headroom a given real-power (kW) load actually needs.
| kW | kVA @ 0.7 | kVA @ 0.8 | kVA @ 0.9 | kVA @ 0.95 | kVA @ 1.0 |
|---|---|---|---|---|---|
| 1 kW | 1.43 | 1.25 | 1.11 | 1.05 | 1.00 |
| 5 kW | 7.14 | 6.25 | 5.56 | 5.26 | 5.00 |
| 10 kW | 14.29 | 12.50 | 11.11 | 10.53 | 10.00 |
| 20 kW | 28.57 | 25.00 | 22.22 | 21.05 | 20.00 |
| 30 kW | 42.86 | 37.50 | 33.33 | 31.58 | 30.00 |
| 50 kW | 71.43 | 62.50 | 55.56 | 52.63 | 50.00 |
| 75 kW | 107.14 | 93.75 | 83.33 | 78.95 | 75.00 |
| 100 kW | 142.86 | 125.00 | 111.11 | 105.26 | 100.00 |
Notice how the gap between columns widens as PF drops: a 100 kW load needs 105.3 kVA of capacity at PF 0.95 but 142.9 kVA at PF 0.7, over 35% more apparent power for the identical real-power output.
Common applications
Cross-referencing the amps-to-kW and kVA charts lets an electrician or facilities manager sanity-check a generator or panel size against a load list without running every calculation from scratch.
Matching a compressor's electrical kW rating to its cooling output in BTU/hr or tons is a routine step when replacing HVAC equipment or estimating a building's total cooling load.
Comparing a US catalog listed in mechanical horsepower against a European catalog listed in metric PS requires the kW-to-HP chart to avoid ordering an undersized or oversized motor.
Generators and UPS units are rated in kVA, but connected loads are usually specified in kW, so the kW-to-kVA chart at the facility's typical power factor is a fast first pass before detailed load studies.
Common mistakes
The 480V column in the top chart assumes single-phase; real 480V services are almost always three-phase, which uses the √3 chart further down. Using the wrong table overstates kW by roughly 1.7x.
The topline amps-to-kW chart assumes a resistive load. Applying it to a motor or transformer without power factor overstates real power by 10-30%, understating the true current the wiring will see.
Chart rows are rounded to convenient increments. For permit calculations and breaker sizing, run the exact numbers through the live calculator rather than interpolating between chart rows by eye.
A European motor nameplate in PS and a US motor nameplate in HP look identical but differ by about 1.4%. Picking the wrong column when cross-referencing catalogs compounds this error across a whole equipment order.
Frequently asked questions
How many kW is 50 amps at 240V?+
12 kW at a power factor of 1.0, using kW = (50 × 240) / 1000. At a more realistic PF of 0.9 for a mixed load, it drops to about 10.8 kW.
What is 1 kW in horsepower?+
About 1.34 HP using the mechanical constant (1 / 0.7457), or 1.34 HP using the electrical constant (1 / 0.746), the two values differ by less than 0.1 HP at this size.
How many BTU/hr is 5 kW?+
About 17,061 BTU/hr, found from 5 × 3412.14. That's roughly the output of a 1.5-ton residential air conditioner.
How many tons of cooling is 10 kW?+
About 2.84 tons, using Tons = 10 / 3.5169. HVAC contractors round this to the nearest half-ton when selecting equipment.
Is a 480V circuit always three-phase?+
No. About 95% of 480V services in commercial and industrial buildings are three-phase, but single-phase 480V does exist in some equipment and utility configurations, so always confirm the phase count on the nameplate or panel schedule before using a chart value.
How do I convert kVA to kW using this chart?+
Multiply kVA by the power factor: kW = kVA × PF. A 50 kVA generator running at PF 0.8 delivers 40 kW of usable real power, read the kVA-to-kW relationship in reverse off the kVA table above.
What power factor should I use if the equipment nameplate doesn't list one?+
Use 0.8 as a planning estimate for a mixed load with motors or electronics, or 1.0 only for known-resistive loads like heaters and incandescent lighting. Measure it with a power meter for anything safety-critical.
How many amps is 25 kW at 480V three-phase?+
About 33.4 A at PF 0.9, using A = (25 × 1000) / (√3 × 480 × 0.9). At PF 1.0 it drops to about 30.1 A.
Is horsepower the same in the US and Europe?+
No. US and UK mechanical horsepower equals 745.7 W, while European metric horsepower (PS or CV) equals 735.5 W, about 1.4% less. Always check which standard a nameplate uses before converting.
How accurate are the chart values compared to the live calculator?+
The chart values are exact for the stated voltage and power factor, computed with the same constants as the calculator above. They only lose accuracy if your actual voltage or PF differs from the column shown, in which case the calculator gives an exact answer for your specific numbers.